Dental articulator and method



Sept. 6, 1955 w. B. FORD DENTAL ARTICULATOR AND METHOD 2 Sheets-Sheet 1 Filed April 24, 1952 zfillllllllllf T lnventor W4 YNE 5. F020 attorney p 6, 1955 w. B. FORD 1 2,716,815

DENTAL ARTICULATOR AND METHOD Filed April 24, 1952 2 Sheets-Sheet 2 5 L45 M/AYN 5/ 0/20 (Ittorneg Zhmentor United States Patent DENTAL ARTICULATOR AND METHOD Wayne B. Ford, Burbank, Calif.

Application April 24, 1952, Serial No. 284,175

6 Claims. (Cl. 32-32) This invention relates in general to artificial dentures, more particularly to novel tooth blocks provided in said dentures, and also to a novel method and means for mounting and setting said tooth blocks in the dentures.

It is a general object of this invention to provide artificial dentures that have balanced occlusion. I achieve balanced occlusion by embodying novel interfitting tooth blocks in the rear or molar sections of the dentures and providing the occlusal surfaces of such blocks with angulation of such degree that, in protrusion relationship of the upper block to the lower, the lower block slides forward against the upper block up onto the full slope or angulation of the occlusal surfaces. In practice, this relative movement creates an opening in the nature of one millimeter or one that allows suitable freedom so there can be an overlap of the anterior teeth in the centric relationship of the dentures. In tooth structures having flat occlusive faces, there can be no opening of correction. Thus, as the lower jaw slides forward, the hinged action of the mandibular joint results in a tipping of the mandible itself which does not allow the anterior teeth to hit correctly in incision. It is another object, therefore, to provide, in a set of dentures, tooth blocks having angulation of the occlusal surfaces of such degree that the anterior teeth are correctly related in incision.

It is of extreme importance that the two sets of tooth blocks be initially accurately related as during a centric relationship of the upper and lower of a set of dentures. Another object of the invention, therefore, is to provide a mechanical but temporary connecting means for said pairs of blocks whereby such accuracy of relationship is assured during the positioning of said pairs of blocks and production of the set of dentures.

A further object of the invention is to provide tooth blocks of the nature indicated that are in balance in all excursions of the mandible. I achieve the same by eliminating all cusps in the bicuspid-molar areas, since cuspal interference will rock or tilt artificial dentures, and use instead the previously mentioned angulated occlusal surfaces formed in continuous transversely sloping planes provided with depressions that define food-attriting raised portions.

The mentioned tooth blocks depend on their efficiency in use on the accuracy with which the same are mounted in the dentures. It is a further object of the invention to provide a novel method for mounting the pairs of tooth blocks so that the same have their plane of occlusion properly related to the models of the mouth used for modeling the denture plates.

The invention also has for its objects to provide such means that are positive in operation, convenient in use, easily installed in a working position and easily disconnected therefrom, economical of manufacture, relatively simple, and of general superiority and serviceability.

The invention also comprises novel details of construction and novel combinations and arrangements of parts, which will more fully appear in the course of the following description. However, the drawings merely show and the following description merely describes one embodiment of the present invention, which is given by way of illustration or example only.

In the drawings, like reference characters designate similar parts in the several views.

Fig. 1 is a vertical sectional view of a conventional articulator and showing a step of the present method wherein the general plane of occlusion of the dentures being made is established.

Fig. 2 is a plan sectional view of Fig. 1.

Fig. 3 is a view, similar to Fig. 1, showing a step of the present method wherein the tooth blocks are located so as to be on the plane of occlusion of the dentures.

Fig. 4 is a plan sectional view as taken on line 4-4 of Fig. 3.

Fig. 5 is a fragmentary sectional view as taken on line 5-5 of Fig. 3.

Fig. 6 is a fragmentary sectional view waxing step of the present method.

The present articulator and method deal with artificial dentures which are comprised of upper and lower plates and with the proper location thereon of tooth blocks 17 and 18 (Fig. 6).

The elficiency of such dentures is, in a large measure, the result of accuracy of placement of the tooth blocks 17 and 18 in the respective acrylic plates of the dentures relative to each other and relative to the gum ridges of the mouth fitted with such dentures. The following describes a novel method for achieving such accuracy of placement of not only the tooth blocks 17 and 18, but also of the other teeth used in such dentures.

In a conventional manner, a set of stone models 30 and 31, respectively upper and lower, is made by impression, as a duplicate of the mouth of the patient. These are made in plaster from the materials used to take the mouth impressions. In the past, these models were mounted in any conventional articulator 32 by sight and guess. Since the plane of occlusion should be substantially horizontal both transversely and front to back, it is important that the same be accurately positioned in the articulator. To this end, a set of wax bite blocks 33 and 34 is made, and said plane of occlusion 35 modeled with the mouth in the accepted sibilant-sounding position. These bite blocks 33 and 34 are tacked together along said line and, after removal from the mouth, the models 30 and 31 are fitted thereinto.

Heretofore, the plane 35 (Fig. l) was guessed at in positioning the blocks in the articulator. According to the present method, the plane is located as by a frame 36 removably mounted in the articulator and having a surface 37 that is held horizontal, and a suitable number of thin gauge pieces 38 angularly adjustable relative to surface 37. Corners or edges of said gauge pieces are introduced into the wax impressions along the plane 35 as shown in Figs. 1 and 2 to hold said plates aligned with surface 37. Thus, with frame 36 in horizontal position in the articulator, stone models 30 and 31 and wax bite blocks 33 and 34 are held accurately while fill-in plaster 39 is applied to secure the models to the articualtor. When this plaster has set, frame 36 is removed, leaving the plaster or stone models 30 and 31 in place in the articular and in their desired relative positions with the wax bite blocks in place.

The plane 35 is now established between blocks 33 and 34. However, said plane, while truly horizontal, may be slightly tipped relative to said blocks. Since it is impossible to model an exactly accurate plane 35 in waxes 33 and 34 while the same are in the mouth, some correction is entailed in establishing a new and accurate plane of occlusion. After the stone models are sealed into the articulator, they cannot be moved for the purpose of coras taken on line 2-2 showing the d recting any discrepancies in their position. Therefore, the models are left as mounted and a new and correct plane of occlusion is established.

In taking the wax bite registration, the lipline is naturally established. Also, the retrimolar pads are marked on the stone model 31 at points known to those skilled in the art. The wax rims 33 and 34 are separated and a plate 41 is placed in the plane common to said lipline and retromolar pad markings. Now, movable fingers or rests 51, carried by plate 41, are swung in the plane of said plate to touch said marking at lipline and pad to test the accuracy of position of plate 41 relative to the stone models. Said plate 41 is provided with a forward adjustable support leg 42, a rearward hinge 43 enabling the same to be swung up when desired, a heightadjustable bracket 44 mounting hinge 43 on the base 45 of the articulator, and a transverse angular adjustment 46 for hinge 43 and plate 41. By means of the foregoing, plate 41 can be placed in a plane common to the mentioned markings and its upper surface now constitutes the new and accurate plane of occlusion to which the dentures are to be formed.

As shown, plate 41 is formed to have a Ushaped opening 47 generally conforming in shape to the shape of the gum ridges 48 of models 30 and 31. In any case, said opening is sufficiently large to fully expose the upper and lower gum ridges, as seen in Figs. 3 and 4. It is while the parts are in this position that the tooth blocks 17 and 18 in pairs, are set in position. Actually, the same are suspended in space between stone models 30 and 31. As seen in Figs. 3 and 4, a pair of discardable spanning rods 49 are temporarily connected at the ends of said tooth blocks and used as supports by means of which said tooth blocks are held in desired position. Fig. 4 shows how the spanning rods 49 are placed on plate 41 so that the tooth blocks 17 and 18 can be shifted relative to gum ridge 48 of the lower stone model 31. Fingers 51 are used to lightly clamp rods 49 to hold said tooth blocks in set position. Then the upper stone block (see Fig. 3) is swung into place and the initial position of said tooth blocks is checked relative to the gum ridge of said upper model. If correction of position of the tooth blocks is indicated, the same is made while rods are lightly clamped. When a desired position is achieved, fingers 51 are tightly clamped, insuring firm location of the tooth blocks in final set position that is absolutely straight both vertically and horizontally relative to the plane of plate 41. Now molten wax is filled in between the lower tooth block 18 and stone model 31, as shown in Fig. 6. In this manner, said tooth blocks may be placed accurately over gum ridge 48, and the line on which blocks 17 and 18 part kept on the plane established by the upper face of plate 41. In the same way, the lower frontal teeth of the lower denture may also be set in Wax against forwardly movable and swingable plate 52 and the wax modeled to the shape and thickness desired for the acrylic material of the plates. The frontal teeth of the upper denture are similarly embedded in wax and modeled as desired.

Since the surface 37 of frame 36 and the upper surface of plate 41 serve the same general purposeto establish the plane of occlusion-frame 36 may be omitted and plate 41 used instead when initially placing the models in the articulator. However, because the bite blocks 33 and 34 are tacked together, it will be necessary to make the plate of two separable sections so that the tacked-together bite blocks may be inserted in the Ushaped opening or space 47. Such separation may be provided for along a line 55 shown in Fig. 4 and fingers 51 used in the same way that gauge pieces 38 were used.

It will be realized that all of the accepted dental techniques have not been described because the same are well known and are employed in the usual way in connection with the above-described method. Thus, centering of the plates, maintaining the lipline regardless of the need for correcting initial discrepancy in the disposition of the line of occlusion, etc., may be carried out as before. However, with a mechanical plane for permanent reference, and with gauges 51 and 52 carried thereby to enable constant check of said plane across the opening 4'7, assurance is had that the teeth will be set accurately on said plane.

After the Waxes 50 have been modeled as desired and the teeth set therein, the same are invested and in the usual manner, the wax replaced by acrylic or like material.

While the invention that has been illustrated and described is now regarded as the preferred embodiment, the construction is, of course, subject to modification without departing from the spirit and scope of the invention. It is, therefore, not desired to restrict the invention to the particular form of construction illustrated and described, but to cover all modifications that may fall within the scope of the appended claims.

Having thus described the invention, what is claimed and desired to be secured by Letters Patent is:

1. A method for locating and setting a mating pair of molar tooth blocks in proper relationship to the gum ridges of a set of plaster models while the latter are positioned in a dental articulator, said method consisting in establishing the plane of occlusion in the space between said models and positioning a plate on said plane, sus pending from said plate said pair of tooth blocks while temporarily connected to and aligned with each other, shifting the connected tooth blocks along the top surface of the plate relative to the gum ridges of the upper and lower plaster model clamping said blocks in place, and filling in molten wax between said models and the tooth blocks of the mating pairs.

2. A method for locating and setting a mating pair of molar tooth blocks in proper relationship to the gum ridges of a set of plaster models while the latter are positioned in a dental articulator, said method consisting in establishing the plane of occlusion in the space between said bite blocks and positioning a plate on said plane, suspending from said plate said pair of tooth blocks while temporarily connected to and vertically and horizontally aligned with each other and with the occlusal faces of said mating tooth blocks coplanar with the upper surface of said plate, shifting the connected tooth blocks along said upper plate surface relative to the gum ridge of the upper and lower plaster models, and filling in molten wax between said models and the lower tooth blocks of the mating pairs.

3. A method according to claim 1 in which the plane of occlusion is established by first providing an initial temporary plane from wax bite blocks of the mouth and in relation to which the models are mounted in the articulator, and then correcting discrepancies in said temporary plane relative to a lipline marked on the lower bite block and the retrimolar points marked on said lower model.

4. The combination with a dental articulator having a dental model-mounting base and a dental model-mounting swingable arm thereabove and a horizontal pivot on which said arm is movable in a vertical plane, of a plate located between said base and arm, a universal mount for said plate adapting the latter to be adjusted in a desired plane relative to said base and a dental model thereon and a vertically adjustable support for said mount and carried by the base, whereby said plate is mounted for both universal and vertical adjustment independent of the swinging movement of the arm and a dental model thereon.

5. The combination with a dental articulator having a base and a swingable arm thereabove, of a plate located between said base and arm, a universal mount for said plate adapting the latter to be adjusted in a desired plane relative to said base, and finger members adjustably carried by said plate and movable in the plane of said plate.

6. The combination with a dental articulator having a base and a swingable arm thereabove, of a plate located between said base and arm, a universal mount for said plate adapting the latter to be adjusted in a desired plane relative to said base, and finger members adjustably carried by said plate and movable in the plane of said plate, said plate having an opening therein shaped to expose the gum ridge of a stone block mounted on the articulator base, and said fingers being movable across said opening.

2,095,665 Greth Oct. 12, 1937 6 Chott May 7, 1940 Hirschhorn Dec. 12, 1950 Zilinski Jan. 30, 1951 Zilinski Jan. 30, 1951 Kinsley Oct. 9, 1951 Donavan June 3, 1952 Scott Sept. 2, 1952 Fox Sept. 2, 1952 Schlesinger Dec. 16, 1952 

